I'll give you the procedure that was given to me at the school for POI/POA testing that has never failed me.
1) You don't need to shoot off a bench but you do need to be steady, if you can't be steady then shoot off a bench, sticks or whatever you need to. Just don't rest your barrels on anything, especially thin English SxS barrels.
2) You need a rear sight so you can repeat your hold. The proper height is two quarters taped together, I use a bit of poster tack to stick them to the gun so they don't fall off with every shot. Apparently one of the English coins is the thickness of two quarters and that's where it came from.
3) Your sight picture should be resting the bead on top of the quarters. I use a 2" orange stick on dot and hold right on it. Do this at 16 yards. It has two purposes:
A) Adjustments of one inch on the target correlate to 1/16" on the sock which is easy to work with. (Irrelevant if both barrels don't shoot where the're supposed to.) The plus side is if the barrels are properly regulated you'll know what stock corrections to make to get it to fit you.
B) Gross problems will be readily apparent at this distance. The gun may well be regulated for 40 yards but it's extremely difficult to estimate the center of a pattern at that distance. Additionally try to hold on a dot at that distance and you'll see you're pissing in the wind, small movements are going to make big changes. For POI you have to eliminate shake, poor sight alignment and poor hold or this is going to be a waste of time. This is when you'll realize that most shotgun triggers are not so great, throw out patterns where you know you had a bad trigger pull. No gun that is grossly off at this distance is going to be magically on at 30 or 40 yards.
4) One shot per piece of paper, don't shoot overlapping patterns when shooting for POI.
5) If you find your barrels are just a little off then back out to the distance you think the gun is regulated for and test again. That's where you can check your pattern to see if it's acceptable at that distance.
Lastly, I use a computer program (Shotgun Insight) which allows me to take digital pictures of my patterns and analyze them. It will give you a graph showing where you aimed and where the center of the pattern hit. When I sent the printout in to the smith for one of my guns he couldn't believe how useful it was. It really illustrates if something is out of wack and helps prevent a company from saying "we shot it and it's fine." Also it lets me check repair work to see if they're blowing smoke up my a**.
Contact me if you want me to run your patterns through the computer and I'll let you know what set up I need to do it. Essentially all you really need to know is what load you're shooting, the distance, hold point and something in the picture for scale.
Last edited by Glocksig; 04/08/13 12:07 PM.
